The present invention generally relates to optical interconnects and systems including optical interconnects. More particularly, the invention relates to apparatus for coupling light emitting and/or light detecting devices and associated electronic components to an optical fiber, modules including the apparatus and components, and to methods of making the apparatus and module.
Systems including optical interconnect devices are often used to transmit information at high data rates. For example, such systems are used for board-to-board, backplane, local area network (LAN), wide area network (WAN) and similar applications. Optical systems are advantageous compared to electrical interconnect systems because optical systems are generally less susceptible to electromagnetic interference, which often results in cross-talk within the system and external noise emission from the system, particularly as the rate of information transfer increases. However, optical interconnect systems are typically relatively expensive compared to electrical interconnect systems, and thus factors such as distance the transmitted signal must travel, bandwidth required by the system, cost, power consumption, signal integrity requirements, and the like are often considered before selecting a type of system.
Typical optical interconnect systems generally include an optoelectronic device such as a light emitting (e.g., laser) and/or a light detecting (e.g., a photodiode) device, an electronic device (e.g., an amplifier and/or a driver) coupled to the optoelectronic device, and waveguide material such as a fiber ribbon cable. The optoelectronic devices are often fabricated such that the active region i.e., the area that emits or receives photons from the waveguide, is on the same surface as electrical connections for coupling the optoelectronic device to the corresponding electrical device. In this case, either the electrical connections or the optical connections must typically undergo an effective ninety-degree bend to allow electrical coupling between the optoelectronic device and electronic device and optical coupling between the optoelectronic device and the waveguide. Prior-art methods and apparatus for accounting for this effective ninety-degree bend are generally expensive to manufacture and/or are relatively inefficient at transferring light between the optoelectronic device and the waveguide Accordingly, improved methods and apparatus for coupling the optoelectronic device, the electronic device, and the fiber are desired.
In addition, prior art systems often include separate substrates for the optoelectronic device and electronic components (e.g., an amplifier and/or driver) associated with the optoelectronic device. Use of separate substrates may undesirably add to the cost and complexity of manufacturing the systems. Accordingly, improved methods and apparatus for forming optical interconnects systems including a reduced number of substrates are desired.
The present invention provides an apparatus for coupling an optoelectronic device and an electronic component to an optical transmission medium or waveguide such as an optical fiber and a method of forming the apparatus. More particularly, the invention provides a method and apparatus for an optical interconnect system which requires a reduced number of substrates to couple the electronic component, the optoelectronic device, and the waveguide.
The way in which the present invention addresses various drawbacks of the now known optical interconnect devices and systems is discussed in greater detail below. However, in general, the improved optical interconnect device and system in accordance with the present invention are relatively inexpensive and easy to manufacture.
In accordance with one embodiment of the present invention, an optoelectronic device and an associated electronic device are formed on the same substrate. In accordance with one aspect of this embodiment, the substrate includes guides configured to receive fibers of a fiber optic cable and to align the fibers with input or output regions of the optoelectronic device. In accordance with a further aspect of this embodiment, the substrate includes a diver, a light-emitting device coupled to the driver, an amplifier, and a light-detecting device coupled to the amplifier. In accordance with yet a further aspect of this embodiment of the invention, a system includes a lens interposed between an optical fiber and the optoelectronic device to increase transmission efficiency of light transferred between the optoelectronic device and the fiber.
In accordance with another embodiment of the invention, a system includes an optoelectronic device and an associated electronic device formed on a first surface of a substrate and receives a transmission medium such as an optical fiber on a second surface of the substrate. In accordance with one aspect of this invention, apertures are formed through the substrate to allow light transmission between the optoelectronic device and the optical fiber.
In accordance with yet another embodiment of the invention, an interconnect system includes at least one optoelectronic device coupled to an associated electronic device, where both are formed on a single substrate and where the optoelectronic device is configured to receive or emit light in a direction away from the surface of the substrate. In accordance with one aspect of this embodiment, the optoelectronic device and the associated electronic device are coupled using wire bonds.